KOI-1257
The planetary system KOI-1257 hosts at least one planet. Note that the system is a multiple star system. It hosts at least 2 stellar components.
| System parameters | |
|---|---|
| Primary system name | KOI-1257 |
| Alternative system names | Kepler-420, KIC 8751933 |
| Right ascension | 19 24 54 |
| Declination | +44 55 38 |
| Distance [parsec] | 900±110 |
| Distance [lightyears] | 2935±359 |
| Number of stars in system | 2 |
| Number of planets in system | 1 |
Architecture of the system
This list shows all planetary and stellar components in the system. It gives a quick overview of the hierarchical architecture.
- Stellar binary, semi-major axis: 5.3±1.3 AU, 9±3 years
KOI-1257 A, stellar object
KOI-1257 b, planet, semi-major axis: 0.382±0.006 AU
- KOI-1257 B, stellar object
Planets in the system
This table lists all planets in the system KOI-1257.
| KOI-1257 b | |
|---|---|
| Alternative planet names | KOI-1257 A b, Kepler-420 A b, Kepler-420 b, KOI-1257.01, KIC 8751933 b |
| Description | KOI-1257 b is a highly eccentric transiting exoplanet in an old, metal-rich binary system. The transits were initially spotted in the Kepler data. Follow-up observations consisting of a joint amateur and professional campaign confirmed the planetary nature of the transits. |
| Lists | Confirmed planets; Planets in binary systems, S-type |
| Mass [Mjup] | 1.4±0.3 |
| Mass [Mearth] | 461±111 |
| Radius [Rjup] | 0.94±0.12 |
| Radius [Rearth] | 10.5±1.3 |
| Orbital period [days] | 86.6477±0.0000 |
| Semi-major axis [AU] | 0.382±0.006 |
| Eccentricity | 0.77±0.04 |
| Equilibrium temperature [K] | 511±50 |
| Discovery method | transit |
| Discovery year | 2014 |
| Last updated [yy/mm/dd] | 14/06/25 |
Stars in the system
This table lists all stars in the system KOI-1257.
| KOI-1257 A | KOI-1257 B | |
|---|---|---|
| Alternative star names | Kepler-420 A, KIC 8751933 A | Kepler-420 B, KIC 8751933 B |
| Mass [MSun] | 0.99±0.05 | 0.70±0.07 |
| Radius [RSun] | 1.13±0.14 | 0.68±0.07 |
| Age [Gyr] | 9±3 | N/A |
| Metallicity [Fe/H] | 0.27±0.09 | N/A |
| Temperature [K] | 5520±80 | 4270±290 |
| Spectral type | G5V | K6V/K7V |
| Visual magnitude | N/A | N/A |
Planet sizes
The following plot shows the approximate sizes of the planets in this system The Solar System planets are shown as a comparison. Note that unless the radius has been determined through a transit observation, this is only an approximation (see Lissauer et al. 2011b).
Habitable zone
The following plot shows the approximate location of the planets in this system with respect to the habitable zone (green) and the size of the star (red). This is only an estimate, using the star's spectral type and mass. Note that if no green band is shown in the plot, then the planet's orbit is far outside the habitable zone. The equations of Selsis, Kasting et al are used to draw the inner and outer boundaries.
Scientific references and contributors
Links to scientific papers and other data sources
https://arxiv.org/abs/1512.00189
|
|
http://exoplanet.eu
|
|
http://arxiv.org/abs/1406.6172
|
This table lists all links which are relevant to this particular system. Note that this is just a summary. More references to the scientific publications and comments can be found in the commit messages. To see these, head over the github or click here to directly go to the git blame output of this system. In the left column of the output you can see the commit message corresponding to each parameter. It also lists the date of the last commit and the person making the changes. Within the commit message, you will find a link to the scientific publication where the data is taken from. Note that this is a new feature and not all system parameters might have a reference associated with it yet. Please help making this catalogue better and contribute data or references!
Open Exoplanet Catalogue contributors
| Contributor | Number of commits | |
|---|---|---|
| Andrew Tribick | ajtribick(at)googlemail.com | 2 |
| Hanno Rein | hanno(at)hanno-rein.de | 3 |
| Ryan Varley | ryanjvarley(at)gmail.com | 1 |
This table lists all people who have contributed to the Open Exoplanet Catalogue. Please consider contributing! Click here to find out how. You can also view all commits contributing to this file on github.
Data download
You can download the xml file corresponding to this planetary system, which is part of the Open Exoplanet Catalogue. All information on this page has been directly generated from this XML file. You can also download the entire catalogue over at github. If you prefer to download the dataset as an ASCII tables, you might find the oec_tables repository useful.
Corrections
If you spot an error or if you can contribute additional data to this entry, please send an e-mail to exoplanet@hanno-rein.de. Please include the corrected xml file and a reference to where the new data is coming from, ideally a scientific paper. If you are fluent with git and github, you can also create a pull request or open an issue on the Open Exoplanet Catalogue repository. Please include the reference to the relevant scientific paper in your commit message.